WASHINGTON — Carmel Martin, the assistant secretary for planning, evaluation and policy development at the Education Department for the past four years, is leaving that post for the Center for American Progress, the center announced Tuesday. Martin will become executive vice president for policy at the liberal think tank, overseeing its policy development.

Martin, whose departure was bemoaned by former department higher education staff on Tuesday, had been considered likely to play a larger role in shaping the department's higher education policy in Obama's second term. She focused heavily on K-12 education in the first term but had played key roles in efforts to bolster state data systems, among other things. And she had reportedly been a more visible presence in postsecondary-related meetings in recent months.

Instead, she joins what has become something of a departmental exodus in recent months. Since before the election, observers have warned that departures of key political appointees and career staff members have left a policy making void on higher education. David Bergeron, the acting assistant secretary for postsecondary education, said in February that he would leave his job at the department.